Vibratory roller for rolling ground surfaces,having tandem - mounted rollers



Jan. 21, 1969 vlTRY 3,422,735

VIBRATORY ROLLER, FOR ROLLING GROUND SURFACES, HAVING TANDEM-MOUNTED ROLLERS Filed May 13, 1966 United States Patent US. Cl. 94-50 7 Claims Int. Cl. E01c 19/23 ABSTRACT OF THE DISCLOSURE A vibratory type ground roller apparatus having a plurality of ground rollers arranged in tandem and a steering train pivotably mounted on the draw bar of the apparatus, said train comprising a ground wheel which is yieldingly urged towards the ground and whose rotary axis is vertically shiftable relative to the rotary axis of the ground rollers.

It is very hard work for an operator to guide vibratory rollers for rolling ground surfaces, having rollers mounted in tandem fashion on a rigid frame around parallel axles, because the lateral force which the operator must exert on the drawbar to produce adequate torque to veer and steer the machine is considerable whether the rollers are vibrating or not, so that the operator becomes very tired, since he has to repeat his action many times during a day.

It has been suggested to mount the two rollers on separate frames articulated to one another, but this construction is very expensive.

The object of the present invention is to provide an improved vibratory roller, and to facilitate the guiding of such machines without making their cost prohibitive.

According to this invention, a vibratory roller, for rolling ground surfaces, provided with tandem-mounted rollers rotating around parallel axles, is characterised by an orientable directing train articulated to the drawbar of the roller and comprising handlebars and at least one wheel adapted to be pressed downwards so as to be retained in contact with the ground. Preferably, the wheels of the directing train are applied to the ground by an auxiliary force to make sure that the wheels contact the ground satisfactorily even if the ground is very uneven.

Embodiments of the invention are shown in the accompanying drawings, wherein:

FIG. 1 is a diagrammatic perspective view of a known ground roller.

FIG. 2 is a diagrammatic perspective view of another embodiment of the invention.

FIG. 3 is an elevation, partly in section, of part of the directing train of a further embodiment of the invention.

FIG. 4 is a diagrammatic elevation, partly in section, of a still further embodiment of the invention; and

FIG. 5 is an end elevation of the directing train of a still further embodiment of the invention.

Referring to FIG. 1 which illustrates a known ground roller, a vibratory roller comprises a frame 1 on which two rollers 2 are tandem-mounted around parallel axles located generally at 3. Associated with the rollers 2 are known mechanisms (not shown) for driving and vibrating the machine. The machine is steered by a directing or steering frame 5 which includes a longitudinally extending arm 5 attached to a drawbar 4. The directing train 5 comprises handlebars 6 and at least one wheel 7 bearing against the ground, and is articulated to the drawbar 4 by a vertical pivot 8. The operator merely has to point Patented Jan. 21, 1969 the directing train in the right direction for the machine to follow.

To make sure that the machine makes contact satisfactorily even with rough ground, a number of wheels 7 may be used having heavily profiled pneumatic tyres, the wheels 7 preferably being pressed against the ground by the means according to this invention shown in FIG- URES 2 to 5. In the embodiment illustrated in FIG. 2, the wheels 7 of the directing train 5 are mounted on axles 9 which are substantially in a vertical plane passing through the pivot 8 and are borne by suspension arms or forks '10 which oscillate, around horizontal pivots 11, on either side of a rear part 5a of the train 5, which part 5a can be straddled by the wheels 7 when the latter are in a raised position.

To force the wheels 7 against the ground, use can be made of a weight or springs, or a pneumatic or hydropneumatic suspension. A hydraulic suspension would not respond quickly enough when the machine passed over rubble or stones, in which case the wheels 7 must be rapily forced on to the ground.

FIG. 3 shows a pneumatic jack 12 pivoted to the directing train 5 at 13 and to the arms 10 at 14. The jack 12 can be supplied with pneumatic fluid by a compressor 15 driven by the motor actuating the rollers. The compressor 15 does not call for much power, and can operate continuously without excessive cost. The air supplied by the compressor is only slightly heated, and the compressor can operate when dry.

FIG. 4 shows a hydropneumatic variant in which a hydraulic jack 16 is pivoted to the directing train 5 at 13 and to the arms 10 at '14. and is connected by a conduit 17 to a pneumatic pressure accumulator 18 having, for instance, a diaphragm, a piston or a bladder. The jack 16 is provided with a filling plug 19, and the conduit 17 has a venting plug 20. The conduit 17 is connected to the accumulator 18 by a valve means 21 which enables the accumulator to be isolated when the pump is disconnected after filling the circuit. The circuit must be completely sealing-tight so that the operator seldom has to replenish the oil. A vibrator 23 is mounted on each axle of the rollers 2.

FIG. 5 shows an arrangement in which the directing train 5 is pivotally mounted on a horizontal shaft 22 which is perpendicular to the vertical pivot 8, thus censuring that the directing wheels 7 adhere very satisfactorily to uneven ground.

Clearly, modifications could be made to the embodiments described hereinbefore, more particularly by the substitution of technical equivalents, without departing from the scope of the invention as defined in the appended claims.

What I claim is:

1. A ground roller apparatus of the vibratory type comprising a frame, a plurality of ground rollers rotatably mounted in tandem on said frame about parallel axes, a steering means comprising a steering frame pivotably mounted relative to said frame about a vertical axis and comprising a steering wheel mounted about a horizontal axis on said steering frame and adapted to roll along the ground and to steer the apparatus pursuant to said steering frame being pivoted about said vertical axis, a pressing means yieldingly urging said wheel against the ground and adapted to permit the rotary axis of said wheel to move vertically relative to said parallel axes pursuant to said apparatus travelling over an irregular ground surface, said steering frame comprising a steering arm pivoted about said vertical axis and extending longitudinally therefrom in a direction away from said ground rollers, a hand gripping means on said arm at a location remote from said vertical axis whereby a person on foot may grip said gripping means and pivot said steering frame about said vertical axis, said steering means comprising a fulcrumed generally horizontally extending suspension armpivotably mounted on said steering frame about a first horizontal axis, said wheel being rotatably mounted on said suspension arm about a second horizontal axis remote from said first axis, said pressing means acting on said suspension arm to pivot same about said first axis in a direction whereby said wheel is urged towards the ground.

2. The apparatus of claim '1, wherein said pressing means acts on said suspension arm at a point thereon intermediate of said first and second axes.

3. The apparatus of claim 1, said second axis and said vertical axis lying substantially in the same vertical plane.

4. The apparatus of claim 1, said pressing means comprising a pneumatic jack interposed between said suspension arm and a vertically fixed part of said steering frame, a gas compressor for feeding said jack, and power drive means for driving said apparatus and drivingly connected to said compressor.

5. The apparatus of claim 1, said pressing means comprising a hydraulic jack interposed between said suspension arm and a vertically fixed part of said steering frame, a pneumatic pressure accumulator connected to said jack.

6. The apparatus of claim 1, said steering means being pivotable relative to said frame about a horizontal axis as well as about said vertical axis.

7. A ground roller apparatus comprising a frame, a plurality of ground rollers rotatably mounted in tandem on said frame about parallel axes, a steering means pivotably mounted relative to said frame about a vertical axis and comprising a steering wheel adapted to roll along the ground and to steer the apparatus pursuant to said steering means being pivoted about said vertical axis, a pressing means yieldingly urging said wheel against the ground and adapted to permit the rotary axis of said wheel to move vertically relative to said parallel axes pursuant to said apparatus travelling over an irregular ground surface, said steering means comprising a horizontally extending circular shaft pivotable in a horizontal plane relative to said frame about said vertical axis, said steering means comprising a plurality of wheels coaxially aligned for rotation about a common rotary axis, the rotary axis of said wheels being defined by a pivot means which is rotatably mounted about said shaft for rotation in a vertical plane whereby the rotary axis of said wheels is concurrently pivotable in a horizontal plane about said vertical axis and also in a vertical plane about said shaft.

References Cited UNITED STATES PATENTS 2,024,184 12/1935 Ritchie 94 2,133,862 10/1938 Kerns.

651,655 6/1900 Deteding 94-50 2,775,925 1/1957 Greiner 94 50 3,066,585 12/1962 Cumpton 94 50 3,071,051 1/1963 Martin 94 50 FOREIGN PATENTS 343,959 2/1931 Great Britain.

JACOB L. NACKENOFF, Primary Examiner. 

